1. Field of the Invention
The present invention relates to a dowel transfer station in dowel driving devices which include a dowel separating and conveying unit constructed, for example, in the form of a cup-shaped oscillating conveyor and a manually operated driving gun to which dowels to be driven in are supplied through a hose line. The dowel transfer station is arranged between the dowel separating and conveying unit, on the one hand, and the hose line conducted to the driving gun, on the other hand. The dowel transfer station includes a reciprocating dowel holder which receives a dowel emerging from the dowel separating and conveying unit and supplies the dowel to the opening of the hose line conducted to the driving gun.
2. Description of the Related Art
Dowel driving devices with manually operated driving guns are known in the art. Devices of this type are produced by various manufacturers and are commercially available under the tradenames "Gannomat Modell 251"; "B.RE.MA Mod. GLN 520"; Ayen-Dupo TE 2" and "Dubelfix Hoffmann". As a rule, the dowel separating and conveying unit is composed of an oscillating conveyor which serves to individually supply the dowels to a dowel transfer station. At the dowel transfer station, the dowel emerging from the oscillating conveyor is grasped by tongs which are movable in their plane and which subsequently transfer the dowel to the opening of the hose line in which the dowel is supplied by means of compressed air to the driving gun. Instead of using oscillating conveyors, other separating units, i.e., Ayen-Dupo TE 2, operate in accordance with a balance beam system, wherein the system is equipped with a diameter calibration and a device for testing the length of the dowels. Dowels which are too thick are automatically calibrated in the calibrating unit to the desired dimension and dowels which are too short are separated out in the device for testing the length of the dowels. This ensures that dowels which are not appropriate for the task at hand are not supplied to the driving gun and do not block the mechanism of the driving gun. These devices have the disadvantage that they operate relatively slowly. In the systems mentioned first whose transfer stations operate with reciprocating tongs, it has thus far not been possible to test the length of the dowels. If the quantity of dowels made available contains dowels which are too long or too short, the dowels are nevertheless conducted to the driving gun where they cause problems and impair the operation of the driving gun. Dowels which do not have the proper dimensions may also cause problems of this type already at the transfer station.